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CATALOGUE 



OF 




f Astronomical and Surveying 



INSTRUMENTS 



MANUFACTURED BY 



Fauth &. Co., 





No. 59 B Street, Corner of First, S. W. 

FEOHTIHG CAPITOL PAEK, 

WASHINGTON, D. C. 




GIBSON BROTHERS, PRINTERS, WASH - ^-ON. 






CATALOGUE 



OF 



Astronomical and Surveying 






INSTRUMENTS 



MANUFACTURED BY 



FA.TJTH & Co., 




No. 59 B Street, Corner of Firg$jfc$k 

FB0HTIN& OAPITOL PABK, \ 

WASHINGTON, D. C. 




Entered, according to act of Congress, in the year 1883, by 

FAUTH & CO., 
in the Office of the Librarian of Congress, at Washington. 



X 



CONTENTS. 



PAGE. 
Awards 7-8 

Introduction 9 

Reflectors 10 

Equatorials 11 

Portable Equatorials 14 

Reconnoitring Draw Telescope, 15 

Transit Circles, Fixed 16 

Portable 18 

Transits 19 

DlPLEIDOSCOPES 21 

Combined Transit and Zenith Instrument 22 

The Coast Survey Prismatic Transit 24 

Zenith Instrument 26 

Chronograph 28 

Astronomical Clock 30 

Spherometer 31 

Altitude and Azimuth Instruments 32 

Theodolites 34 

Engineer's Transit 37 

Solar Attachment 38 

New Quick-Levelling Tripod 42 

Reconnoissance and Mining Transit 43 

Levelling Instruments 44' 

" Instrument and Gradientor 45 

Engineer's Y Level 46 

Locke's Hand Level 47 

Levelling-Rods, Chains, and Tapes 47 

Plane Table 48 

Three- Arm Protractor 49 

iii 



IV CONTEXTS. 

PAGE. 

Tide Gauge 49 

Magswtomsfsb 50 

Dep Cercee 51 

Sextant 52 

Aeteficiae Horizon 52 

Prismatic Compass 53 

Heliotropes , 53 

Contact-Slede Apparatus 54 

Spectrometer 57 

Spectroscopes ■ 58 

Deffractiox Gratdtgs 59 

Eye-Pieces am) Micrometers 60 



international ||UfpiiWfy 

PHILADELPHIA, 1876. 



Hie United States Centennial Commissi 'on has examined 
the report of the Judges, and accepted the following reasons, 
and decreed an award in conformity therewith : 

Philadelphia, December 14th. 1876. 

REPORT ON AWARDS. 



Product, ASTRONOMICAL AND SURVEYING INSTRUMENTS. 
Exhibitor, FAUTH & CO., Washington, D. C, U. S. 

The undersigned, having examined the product 
herein described, respectfully recommend the same 
to the JJ. S. Centennial Commission for Award, for 
the following reasons, vis. : 

For excellence in design and construction of the 
Instruments exhibited — consisting of an S-feet 
equatorial Telescope, completely mounted, with a 
6\-incli object glass, by A. Clark & Sons; an Alt- 
Azimuth Instrument, with 12-inch horizontal circle 
read by three, and 10-inch vertical circle, read by 
two micrometer- microscopes with radial illumina- 
tion, and provided with chambered levels of first- 
class accuracy ; also a Transit-Theodolite, and a 
levelling Instrument of lesser size. 

J. E. HILGARD, 

Signature of the Judge. 

APPROVAL OF GROUP JUDGES. 

E. LEVASSEUER, J. SCHIEDMEYER, 

F. A. P. BARNARD, JAMES C WATSON, 
JOSEPH HENRY, GEO. F. BRISTOW, 

P. F. KUPKA, ED. FAVRE PERRET. 

J. true copy of the record. FRANCIS A. WALKER, 

[SEAL] Chief of the Bureau of Awat*ds. 

Given by authority of the D. S. Centennial Commission. 

A. T. GOSHORN, 

Director General. 

J. L. CAMPBELL, J. R, HAWLEY, 

Secretary. President. 

v 




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INTRODUCTION. 

IN presenting a new illustrated Catalogue and Price-List, we take this 
occasion of thanking our friends for past favors and to solicit a con- 
tinuance of then patronage. Our constant aim is to improve our 
instruments, increase their accuracy and simplicity, and make then use 
pleasant and convenient. 

This Catalogue contains only the more important of our manufactures, 
instruments and apparatus that have been designed for special purposes 
not being included. We do not wish to occupy space in printing testi- 
monials : but for every instrument herein mentioned we refer to parties 
using them, who will testify as to their worth. 

The prices are put as low as good workmanship and the best of 
materials will allow. 

We use only the very best objectives, well corrected for chromatic and 
spherical aberration. 

Our graduations are always on solid silver, unless otherwise mentioned, 
and we call special attention to the beauty and correctness of our 
divisions. 

Our level vials are all ground, and their sensibility is in accordance 
with the use of the instrument for which they are intended. Our finest 
levels, which are chambered for the regulation of the bubble in changes 
of temperature, are ground to a radius from 900 to 1,200 feet, and are 
filled with pure ether. The report of the judges of the Centennial 
Exposition fully attests the excellence of our levels. Since then we have 
made great improvements in their manufacture, and can refer to nume- 
rous parties in different parts of the country as to their excellent 
performance. 

The weight of our instruments is carefully considered in connection 
with their use. Those intended for purely astronomical or the higher 
grades of geodetic work, while not of excessive weight, are yet so con- 
structed as to insure perfect stability. Those the use of which neces- 
sarily involves much transportation by hand are so constructed that, 
while the weight is materially decreased, the strength required is 
obtained by a judicious and careful distribution of the metal. 

All portable instruments, with then accessories, are packed in neat 
boxes, firmly and conveniently arranged, so they can be put in and taken 
out without trouble. 

Terms net cash. 

Deposits will be required on orders from persons un- 
known to us. 



REFLECTORS. 

Lovers of the study of Astronomy who cannot afford the 
necessarily great expense of a refractor will find much satis- 
faction in the use of a reflector. 

Having had numerous inquiries for this class of instru- 
ments, we have arranged with Mr. I. A. Brashear to furnish 
us with his deservedly -celebrated speculas and flats, which we 
mount with or without clockwork, as purchasers may desire. 
We shall shortly issue a price-list of reflectors, and merely 
state in advance that a 6-inch one can be furnished for about 
$200.00, ranging up to $800.00 for a 15-inch, completely 
mounted on an equatorial stand without circles or clockwork. 



FAITTH & CO., WASHINGTON, I). C. 



11 




No. I. 

EQUATORIAL. 



12 



FAUTH & CO., WASHINGTON, D. C. 




No. 2. 

EQUATORIAL. 



FATJTH & CO., WASHINGTON, D. C. 13 

Cuts Nos. 1 and 2 show two styles of Equatorials made by us. 
No. 1 is intended to be mounted on a brick or stone pier, which is 
especially to be recommended for Telescopes of large size. We have, 
however, built several of them with iron piers. No. 1 is then like No. 2, 
complete in itself, ready to be set up in the observatory. 

We have added several important improvements to these instruments : 
The Telescope can be moved in R. A. without stopping the clock or 
disengaging the worm. When moved sufficiently the clock acts again 
with the regular rate, without previous clamping. If desired, an ad- 
ditional R. A. circle is provided, driven by an auxiliary clock-work, which 
is kept running. An index shows the R. A. of the point to which the 
Telescope is then directed. 

The rate of the driving-clock is readily changed from siderial to lunar. 
Our Equatorials are constructed with the utmost exactness, and every 
one is provided with the following accessories : 

Finder. — A number of micrometrical and astronomical eye-pieces ; 
transit eye-pieces and sun-shades; improved position micrometer, with 
parallactic eye-piece movement, fine movement for spider line, and rapid 
movement for entire micrometer to traverse the field. The micrometer 
head is divided on silver ; the whole revolutions are read off on a separate 
dial, which, in our opinion, is the prettiest device for recording whole 
turns. The position circle is divided on silver, reading by opposing 
verniers and microscopes to minutes or hundredths of a degree. Clamps 
and tangent-screws, or, if desired, rack and pinion movement. 

Large Declination and Hour Circles, divided on silver, and reading 
with two verniers and microscopes to five seconds of arc and single 
seconds of time respectively. Coarse graduation, with pointer, for con- 
venience in setting, is put on the edge. 

Driving-Clock with conical pendulum connected with polar axis ; can 
be thrown in and out of gear from eye-end of Telescope ; additional 
tangent-screw motion in R. A. and Decl. by means of rods and handles. 
Illuminating lamps attached to end of declination axis. 
No. 1. — Equatorial Telescope, of 4-inch aperture, with six eye- 
pieces, fitted up as above $975 00 

" 2. — Same, without clock-work or micrometer * 700 00 

" 3.— " 5-inch aperture 1,400 00 

" 4. — "■ without clock-work and micrometer 1,100 00 

« 5._ « 6-inch aperture 1,800 00 

" 6. — " without clock-work and micrometer 1,500 00 

« 7._ « 7-inch aperture 2,500 00 

« 8.— " 8 " " 3,000 00 

- 9.— " 9 " " 4,000 00 

" 10.— " 10 " " 5,500 00 

The prices of larger instruments may be had on application. 



14 FAUTH & CO., WASHINGTON, D. C. 




No. II. 

PORTABLE EQUATORIAL. 



FAUTH & CO., WASHINGTON, D. C. 15 

Astronomical Telescope, mounted equatorially on a strong tripod 
stand, with or without circles and tangent-screw motion. 

No. 11. — Equatorial Telescope, of 3-inch aperture, mounted as 
above, with finder, silvered circles, tangent-screw 
motion, sun-shade, terrestrial and astronomical eye- 
pieces $300 00 

No. 12. — Same, without circles or tangent-screw motion 220 00 

No. 13.— Same, 4-inch aperture, like No. 11 400 00 

No. 14. — Same, without circles, etc 320 00 



^ 



KEC0NN0ITKING DBAW-TELESCOPE. 

These are very convenient to carry. The Telescope, which has a fine 
objective of two inches aperture, closes up in a leather case about 12 
inches long, with straps attached, and is easily fastened to the stand by 
a circular clamp. The stand has a small divided circle for roughly 
measuring angles. Stadia wires are inserted in the eye-piece for measur- 
ing distances. The stand, when folded, forms a round staff of about 
2 inches diameter. 

No. 15. — Reconnoitring Draw-Telescope, 2-inch aperture, as de- 
scribed above $80 00 

Note. — If Heliotrope fixtures are desired, (see cut No. 62,) con- 
sisting of two plate-glass mirrors and two sight-rings, it 
increases the price 20 00 

Clamp and screw attachment, to screw into a tree or post, extra. 7 50 

The above Telescope, without the stand 30 00 



16 FAUTH & CO., WASHINGTON, D. C. 

FIXED TKANSIT INSTRUMENTS 




No. 16. 

TRANSIT CIRCLE. 



FAUTH & CO., WASHINGTON, D. C. 17 



No. 16. — Transit Circle, with Telescope of about 8 feet focal 
length and 6 inches aperture. Circles three feet in diameter, 
one divided into five-minute spaces, which are read off by 
means of 4 micrometer-microscopes to single seconds. The 
microscope-holder is in the form of a pulley concentric with ' 
the circles, allowing the ready shifting of the microscopes 
to any part of the graduation. The other circle serves as a 
finder, and is provided with a coarse graduation. Clamp and 
tangents by means of rods and handles. Illumination regu- 
lated by means of a milled head near eye-end. The pivots are 
about two inches in diameter, made of hardened steel or phos- 
phor bronze. The level, of best quality, is read by means of 
a mirror. K. A. and Decl. micrometer with parallactic eye- 
piece motion. Iron piers coated with asbestos and covered 
with mahogany; the cut shows it without this covering. 
Six micrometer eye-pieces and one diagonal. Price $4,000 00 

No. 17. — Same, without circles and microscopes; two 6-inch 
setting circles with level alidades attached near the eye- 
end 2,500 00 

No. 18. — Same as No. 16 ; telescope 5 inches aperture ; circles 

30 inches diameter ; 4 microscopes . 3,000 00 

No. 19. — Same, without the large circles, but with two finders. 2,000 00 

No. 20. — Transit Circle, with telescope of 4 inches aperture; 

circles 24 inches diameter ; in other respects like No. 16. . . 2,400 00 

No. 21. — Same, without the large circles, but with two finders. 1,900 00 

Collimators, revolving in Y's, with sensitive level over tele- 
scope ; micrometer eye- piece according to size of objective, 

from $250.00 upwards. 

The above prices include reversing apparatus and observing chair, 

with arrangement to raise and lower the back. 

Note. — These instruments can be mounted upon stone or brick 

piers, which is, perhaps, the better plan. 

When, hi 1877, we made the Princeton Meridian Circle, we guaranteed 

the graduation to be within one second. A critical examination by Prof. 

C. A. Young shows the graduation to be much better than that. Since 

then we have improved our Dividing Engine to such an extent that we 

guarantee our graduation to be within one quarter second. 



B 



18 



FAUTH & CO., WASHINGTON, D. C 

SMALLEE TRANSITS. 




No. 22. 

TRANSIT CIRCLE. 

No. 22. — Transit Circle, of three inches aperture, and circles of 
16 inches diameter. One of the circles is coarsely divided 
on the edge, and serves as a finder. The other is divided into 
5-minute spaces, read by two micrometer-microscopes to 
single seconds. The micrometers can be transferred from one 
pier to the other. Sensitive striding level, read by means of a 
mirror. R. A. and Decl. micrometer, level over micrometer- 
holder ; a level is attached to the telescope for measuring 
differences of zenith distances. The reversing apparatus 
allows the instrument to be reversed with the greatest ease. 
The iron stand is provided with the necessary adjusting 



FAUTH & CO., WASHINGTON, D. 0. 



19 



screws for moving in altitude and azimuth. The instrument 
is complete in itself, ready to be put on pier, and is provided 
with mercury basin, diagonal, direct and collimating eye-piece, 

lamps, etc. Price $1,650 00 

No. 23. — The same, with four-inch telescope 1,800 00 




No. 24. 



3-INCH TRANSIT. 



20 



FAUTH & CO., WASHINGTON, D. C. 



No. 24. — Transit Instrument, of 3 inches aperture, about 3J 
feet focus. The axis carries two 12-inch circles, one reading 
to 10 seconds, the other to minutes ; both are divided on 
the edge. The fine circle carries the latitude level. The 
striding level over the axis is read by means of a mirror. 
The iron stand has the necessary adjustments for altitude 
and azimuth. Reversing apparatus, mercurial basin, diag- 
onal, direct and collimating eye-pieces, lamps, etc. Price. .$1,000 00 

No. 25. — The same, with telescope of 3 inches aperture and 
about 3^- feet focal length. 6-inch setting circle, with level 
alidade on axis ; delicate striding level ; glass micrometer 
instead of spider lines ; direct and diagonal eye-piece, with 
parallactic movement ; improved clamp. One of the Y's 
can be moved in azimuth, the other in altitude, and there be 
firmly clamped. Reversing apparatus, lamps, etc. ........ 790 00 




No. 26. 



FAUTH & CO., WASHINGTON, D. C. 21 

Cut No. 26 represents a smaller Transit of 2 J inches aperture, 
and about 30 inches focus. The axis carries a 6-inch finding 
circle, with level alidade ; the striding level is chambered and 
reads to single seconds ; glass diaphragm ; direct and diagonal 
eye-pieces, with sun-shades, lamps, etc. The instrument is 
adjustable in altitude and azimuth, and is in all respects, ex- 
cept in size, like the preceding ones. Price of this instru- 
ment, without reversing apparatus $600 00 



SMALL TRANSITS. 

Small Transits, suitable for watch and clock makers for taking time. 
The stand is similar to the one shown on cut No. 26. The Y's have no 
adjustment, and the telescope is without clamp or circle ; a good 
striding level, prismatic eye-piece with sunshade and glass micrometer 
are provided. 
No. 27. — Transit, with telescope of 1\ inches aperture, 16 inches 

focus $165 00 

No. 28. — Same, with telescope of 1^ inches aperture 140 00 



DIPLEID0SC0PES, 

These small instruments are excellent for the determination of 
time ; the telescope is about 4 inches in length ; the stand is 
provided with adjustments to get it into the meridian. Price. $35 00 



22 



FAUTH & CO., WASHINGTON, D. C. 



PORTABLE INSTRUMENTS. 

All the following Field instruments are packed complete in boxes 
and provided toith the following accessories: Shade, screw-drivers, ad- 
justing-pins, plumb-bob, reading-glass, and dust brush. 




No. 29. 

COMBINED TRANSIT AND ZENITH INSTRUMENT, 
as devised by Prof. G. Davidson, U. S. C. & G. S. 



FAUTII & CO., WASHINGTON, D. C. 23 

No. 29. — The frame of this instrument consists of two parts, 
the upper part with the uprights revolving upon the lower, 
to which it can be firmly clamped if used as a Transit. When 
used as a Zenith instrument, the clamp-screws are removed ; 
stops and tangent-screw motion for turning it exactly 180° 
around are provided. Two verniers and scale are attached to 
the upper and lower base. The telescope has a clear aperture 
of 2J inches, and about 28 inches focal length. It is provided 
with micrometric eye-piece; two setting circles, divided on 
silver, and reading to minutes, attached to the telescope-tube 
near the eye-end ; one of these carries the delicate zenith level, 
which reads to single seconds and is chambered; in addition, 
also, an ordinary finding level. The clamp is the latest im- 
proved pattern, and need not be carried around with the tele- 
scope when reversing. The pivots are of phosphor bronze, 
and finished with the utmost care ; bearings are agate. The 
illumination is effected through the pivots ; the striding level 
is chambered, and reads to single seconds. A Eamsden eye- 
piece, diagonal eye-piece, two illuminating and one reading 
lamp, are provided. The stand folds and is packed in box 
with the telescope. Price, complete $990 00 



24 



FAUTII & CO., WASHINGTON, D. C. 



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FAUTH & CO., WASHINGTON, D. C. # w 25 

This form of transit, suggested by Steinheil, designed by G. N. Sseg- 
niuller, was made by us for the United States Coast Survey. It 
is intended to be set up in the prime vertical, the telescope 
pointing east and west. By the use of a prismatic objective, any 
star passing the meridian will be reflected and seen in the field 
when the instrument is set up correctly; by turning it in its bear- 
ings it will sweep the meridian. The pivot-rings are of phosphor 
bronze, and, to avoid flexure as much as possible, these rings are again 
connected by a tube, so that the telescope body is really double. By 
one of the three setting-screws the instrument is moved in azimuth. It 
is provided with a reversing apparatus, which also carries the illumi- 
nating lamp. The fine level over the telescope is held by a projection 
from the reversing apparatus, which secures the great advantage, that 
the level need not be taken off on reversing the instrument ; it remains 
on whether observing in the zenith or horizon. The setting-circle is 
attached behind the micrometric eye-piece with level alidade, divided on 
silver, and reading to minutes. It also carries the latitude level, which 
is chambered, and reads to single seconds. This instrument, being very 
simple and portable, is especially adapted for work in a rough or moun- 
tainous country. 

No. 30. — Telescope of 2 J inch clear aperture, packed complete 
in box, with two eye-pieces, illuminating and reading lamp, 
and all accessories $790 00 



26 # FAUTII <fe CO., WASHINGTON, D. C. 




No. 31. 

ZENITH INSTRUMENT. 



FAUTH & CO., WASHINGTON, I). C. 27 

Above cut represents the form of Zenith Instrument as used in the U. 
S. C. & G. Survey and the U. S. Corps of Engineers. The telescope 
swings on a horizontal axis, which is fastened to a vertical axis, and can 
therefore be moved into any position. It is especially adapted for the de- 
termination of differences of zenith distances. The horizontal circle is 
provided with two stops, in order to bring the telescope into the meridian. 
The telescope carries a circle with the latitude level and is provided with 
a micrometer eye-piece. We make several sizes of these instruments. 
No. 31. — Zenith Instrument, of 2 inches aperture, about 28 

inches focal length ; 10-inch horizontal circle ; striding level 

over horizontal axis ; fine latitude level attached to circle ; 

micrometer eye-piece ; packed complete $700 00 

No. 32. — Zenith Instrument, as above, with telescope of 1^ 

inches aperture 350 00 



28 



FAUTH & CO., WASHINGTON, D. 0. 




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FAUTH & CO., WASHINGTON, D. C. 21) 

Cut No. 33 represents our style of Chronograph, which, for com- 
pactness and regularity of action, cannot be surpassed. It is 
noiseless in its action, and the governor regulates the speed so 
perfectly that the second marks form a perfect straight line. 
The cylinder is 14 inches long and 7 in diameter, and runs 
about 2 1 - hours, with three feet fall and a weight of about 
18 lbs. Sffigmuller's maintaining power, however, allows 
the winding up without affecting the rate. The clock- 
work is strong enough to drive 3 or 4 cylinders, which can 
readily be attached. By pushing a button the speed of the 
cylinder is doubled, which is very convenient in exchanging 

clock-signals in longitude work. Price $350 00 

Each additional cylinder, with frame, carriage-slide, and magnet 150 00 
Chronograph paper for the above, per 100 sheets 1 50 



30 



FAUTH & CO., WASHINGTON, D. 0. 




No. 34. 

ASTRONOMICAL CLOCK, 



FAUTH c* CO., WASHINGTON, D. C. 



31 



No. 34. — Astronomical Clock, with either Dennison's gravity or 
dead beat escapement with jewelled pallets. The pendulum 
is compensated and weighs about 40 lbs. We use Prof. C. A. 
Young's break circuit attachment, which gives no spark, thus 
saving the contact points from oxydation. Price $450 00 




No. 35 

SPIROMETER, 
as devised by Prof. Wm. Harkness, U. S. N, 



A beautiful and exceedingly accurate instrument for measuring 
the inequality of pivots ; much more reliable and expeditious 
than the contact level. As made by us, it will measure pivots 
from 2 \ inches down to the smallest size. The round glass disc 
on which the three legs rest is perfectly flat ; the screw is made 
with the utmost exactness, bearing on a jewelled centre, and 
the nut is so constructed that there can be no dead motion. 
Price, in box $50 00 



32 



FAUTH & CO., WASHINGTON, D. C. 



INSTRUMENTS FOR MEASURING HORIZONTAL AND VERTICAL ANGLES. 




From Gebbie &Barrie's "Masterpieces of the U. S. International Exhibition, 187b. 

No. 36. 

ALTITUDE AND AZIMUTH INSTRUMENT. 



FAVTI1 & CO., WASHINGTON, D. C. ?>3 

ALTITUDE AND AZIMUTH INSTEUMENTS. 

Cut No. 36 represents one of our instruments, which was on exhibition 
in the International Exhibition at Philadelphia, for which we received 
an award. 

It is of superior construction, and differs from other instruments of 
this class in many important particulars. Not being a " repeating in- 
strument," strictly speaking, and, therefore, not liable to the defects 
inherent to repeaters, yet both the horizontal and vertical circles can be 
shifted for position, so as to bring a different part of the graduation 
under the microscopes. The circles are divided on silver into five-minute 
spaces, reading by micrometer microscopes to single seconds. The 
standards radiate out from the centre, and are high enough to let the 
telescope swing through. The pivots of the telescope axis rest on agate, 
and are made of phosphor bronze ; a delicate striding level, reading to 
seconds, over the pivots, is provided ; illumination through pivots ; the 
horizontality of the microscopes for vertical circle is controlled by a 
chambered level, reading to seconds. 

Both circles are entirely free of clamps and tangent- screws, these being- 
attached to a collar, so as not to produce any strain. 

No. 36. — Altitude -Azimuth, as described above; horizontal 
circle eighteen, vertical circle twelve inches in diameter; 
former reading by three, and latter by two microscopes ; 
telescope 3-inch clear aperture, 28 inches focal length, with 
micrometric eye-piece ; levels are chambered, and read to 
seconds ; packed complete in two boxes, with positive and 
diagonal eye-piece, two lamps, and all accessories $2,000 00 

No. 37. — Same, without vertical circle, and standards only high 

enough for observation of polaris 1,200 00 

No. 38. — Same as No. 36, and exactly like cut ; horizontal circle 
twelve, vertical circle ten inches in diameter ; former reading 
by three, latter by two microscopes. Telescope 2J-inch 
clear aperture, 24-inch focus ; packed complete 1,300 00 

No. 39. — Same, without vertical circle ; standards as in No. 

37 ; telescope 2-inch aperture ; packed complete 800 00 

No. 40. — Same as No. 39 ; circle reading by two instead of 

three microscopes 700 00 

No. 41. — Same as No. 36, and shown on cut ; horizontal circle 
ten, vertical circle seven inches in diameter ; former reading 
by three microscopes to seconds, the latter, by means of 
level alidade, to ten seconds. Telescope swinging through 
2 inches aperture, and about 18 inches focal length ; packed 
complete 850 00 

c 



34 



FAUTH & CO., WASHINGTON, D. G. 



No. 42. — Same, but without the vertical circle ; telescope not 

swinging through : packed complete 650 00 

No. 43. — Same as No 42 ; the circle reading by two instead of 

three microscopes 550 00 




No. 44. 

IO-INCH THEODOLITE. 

Cut No. 44 represents a Theodolite, of which we have made a 
great number. It is especially adapted for purposes of in- 
struction, and is in every respect a first-class instrument. The 
circle — which shifts for position — is read by two micrometer- 
microscopes, and also two verniers ; the telescope has an aper- 
ture of If inches and about 16 inches focus ; improved clamp, 
sensitive striding level, and field illumination for azimuth ob- 
servations. Packed complete $550 00 



FAUTH & CO., WASHINGTON, 1). C. 

THEODOLITES. 



35 




No. 45. 

10-INCH REPEATING THEODOLITE. 

No. 45. — This cut represents a 10-inch Repeating Theodolite, 
as made by us for the U. S. C. & Geodetic Survey. Circle is 
10 inches diameter, reading by two verniers and microscopes 
to 5 or 10 seconds. The telescope is of If inches aperture 
and about 16 inches focus ; improved clamps and tangent- 
screws ; sensitive level over telescope, and field illumination 

for azimuth observations. Packed complete $450 00 

In cut 45 the verniers are read off by means of a prismatic arrange- 
ment, the instrument having been designed for a particular purpose. 
The above price does not include this nor the eye-piece micrometer. 
No. 46. — Eight-inch Repeating Theodolite, like No. 45. Two 
verniers reading to 5 or 10 seconds ; telescope 1^-inch aper- 
ture and 15 inches focus, with delicate striding level. Packed 
complete $375 00 



36 



FAUTII & CO., WASHINGTON, D. C. 



Note. If any of the above instruments are to read to 5 seconds 

instead of 10, the cost will be $25.00 additional. The circles can also 

be provided with cover at an increase of $10.00. 

Strong double-leg tripods for any of the above instruments $15 00 




WlllllllB 

No. 47. 

8-INCH THEODOLITE. 



FAUTI1 & GO., WASHINGTON, D. C. 



37 



No. 47. — Kepresents an 8-inch Theodolite, of which quite a num- 
ber have been made by us for the U. S. C. & G. Survey. The 
circle, which shifts for position, is 8 inches diameter, divided 
into 10-minute spaces, and is read by means of two micrometer- 
microscopes. The telescope l^as an aperture of If inches and 
about 18 inches focus. Improved clamp, sensitive striding 
level, and field illumination. Price, with stand $425 00 




No. 48. 

ENGINEER'S TRANSIT. 



38 FAUTH & CO., WASHINGTON, D. 0. 

The preceding cut represents one of our complete high-grade Engineer 
Transits. It differs from those of the ordinary construction in its great 
lightness and strength, by judicious ribbing and bracing and the use of 
hard metal. The standards are not of the common construction, but are 
cast in one piece on a ring fitting tightly around the compass ring. 
Each Y has three legs, the two outer ones being curved so as to stand 
well in towards the centre of the plate, while the middle one is directly 
under the bearing. By thus casting a great many parts in the whole, 
which are usually made in pieces and screwed together, the instrument, 
while it is very much stronger, stays also better in adjustment. The 
centres are long, compound, and of hard metal ; the graduation is on 
solid silver ; the telescope is balanced in axis and reverses at both ends ; 
shows objects erect unless otherwise ordered ; it is perfectly achromatic, 
defines sharply, and magnifies 22 diameters ; the tangent-screws are 
made of German silver and work with a beautiful smooth motion, with- 
out any dead play ; compass needle 5 inches long, swinging on jewelled 
centre. Ground levels. 

No. 48. — Transit, as shown in cut. Circles 6J inches diameter, 
divided on silver, reading by two verniers to 30 seconds ; ivory 
shades to throw light on the verniers. The compass plate 
reaches over and forms a cover for the circle ; the vertical 
circle is read to minutes. Telescope reverses at both ends, 
has an aperture of 1J inches with either terrestial or astro- 
nomical eye-piece ; the compass needle is 5 inches long ; sen- 
sitive level on telescope ; Stadia lines for distance measure- 
ments ; centring arrangement for bringing instrument over a 
given point ; adjustable plumb-bob. The instrument com- 
pletely packed, with tripod $275 00 

Note. — The above instrument we also make with three instead 
of four levelling screws, double verniers on vertical circle, 
striding level over telescope axis, and horizontal circle reading 
to 10 seconds ; field illumination. Price $350 00 

S0LAE ATTACHMENT. 

We take pleasure in bringing before the engineering profession a new 
form of Solar Attachment, invented and patented by G. N. Saegmuller, 
which is the simplest and most accurate ever devised. Attached to any 
Engineer's Transit, the true meridian and deviation of the needle can be 
obtained with far greater accuracy than with any solar attachment yet 
invented. 



FAUTH & CO., WASHINGTON, D. C. 



39 




No. 49. 



TRANSIT, WITH SOLAR ATTACHMENT. 



40 



FAIJTH & CO., WASHINGTON, D. C. 



The foregoing cut represents the " Solar Attachment " fixed to an 
Engineer's Transit. It consists essentially of a small telescope and level, 
the telescope being mounted in standards, in which it can be elevated 
or depressed. The standard revolves around an axis, called the polar 
axis, which is fastened to the telescope axis of the Transit Instrument. 
The telescope, called the " solar telescope," can thus be moved in altitude 
and azimuth. It is provided with shade-glasses to subdue the glare of 
the sun, as well as a prism to observe with greater ease when the decli- 
nation is far north. Two pointers attached to the telescope to approxi- 
mately set the instrument are so adjusted that when the shadow of the 
one is thrown on the other the sun will appear in the field of view. 

Adjustment of the Apparatus. 

This is very simple, and requires less work even than to adjust the 
common Transit. 

First. Attach the "polar axis" to the main telescope axis in the 
centre at right angles to the line of collimation. The base of this axis is 
provided with three adjusting-screws for this purpose ; by means of the 
level on the solar telescope this condition can be readily and accurately 
tested. 

Second. Point the transit telescope — which instrument we assume 
to be in adjustment — exactly horizontal and bisect any distant object. 
The transit level will then be in the middle of the scale. Point the 
" solar telescope " also horizontally by observing the same object, and 
adjust its level to read zero, for which purpose the usual adjusting-screws 
are provided. 

Directions for using the Attachment. 

First. Take the declination of the sun as given in the Nautical Al- 
manac for the given da} T and hour, and correct it for refraction and 
hourly change. Incline the transit telescope until this amount is indi- 
cated by its vertical arc. If the declination of the sun is north, depress 
it ; if south, elevate it. Without disturbing the position of the transit 
telescope bring the solar telescope to a horizontal position by means of 
its level. The two telescopes will now form an angle which equals the 
amount of the declination. 

Second. Without disturbing the relative positions of the two tele- 
scopes, incline them and set the vernier to the latitude of the place. 

The vertical axis of the "solar attachment" will then point to the 
pole, the apparatus being in fact a small Equatorial. 

By moving the transit and the " solar attachment " around their re- 
spective vertical axis, the image of the sun will be brought into the field 
of the solar telescope, and after accurately bisecting it the transit tele- 
scope must be in the meridian, and the compass-needle indicates its 
deviation at that place. 



FATJTH & CO., WASHINGTON, D. C. 41 

Advantages of the " Solar Attachment" over the Old Form. 

First. It is more accurate. 

Second. It is simpler and easier of adjustment. 

Third. It is much cheaper. 

It is superior to all forms hitherto used as the transit is to the ordinary 
compass, or as a telescope is to common sights. For the ordinary sur- 
veyor's compass the degree of accuracy of the old attachment will answer, 
although even on a compass our k ' solar attachment " would be an im- 
provement. 

When angles are laid off with a transit, however, it is certainly going 
back a step to attempt to establish a meridian with a less precise instru- 
ment, or one that has less pointing power. 

The sights of an ordinary solar compass consist merely of a small lens 
and a piece of silver with lines ruled on it placed in its focus. This is 
simply a very primitive telescope, since the exact coincidence of the suns 
image with the lines has to be determined by the unaided eye, or at best 
with a simple magnifying glass. 

That far greater precision can be attained by means of a suitable 
telescope is apparent ; in fact, the power of the solar telescope is in 
keeping with the transit telescope, as it should be. 

A glance at the cut will show that the " solar attachment " is far simpler 
than the ordinary form. By raising or depressing, it can be set to north 
or south declination. To effect this with the ordinary solar compass 
two sets of primitive telescopes — one answering for north, the other for 
south declination — are provided, which are difficult to adjust. 

The addition of the level on the solar telescope dispenses with the 
declination arc altogether, the arc or circle on the transit also serving 
for that purpose in conjunction with it. 

This " solar attachment " is in fact the only one which should be used 
in connection with a Transit Instrument. It solves the solar problem, 
s has been attested by the leading astronomers and engineers who have 
seen and used it. 

Price of Solar Attachment, complete, with sun-shades $40 00 

Rectangular Prism to attach to eye-piece 5 50 



42 



FAUTH & CO., WASHINGTON, D. 0. 



NEW QUICK-LEVELLING TKIPOD-HEAD, WITH 
SHIFTING-PLATE. 

Patented by G. N. Sjegmuller, Washington, D. C. 




No. 50. 

The engravings represent a new form of Quick-Levelling Tripod, which 
is the simplest and most convenient yet devised. It consists of two 
circular discs, which are wedge-shaped — that is, thicker on one side than 
the other. They are interposed between the levelling-screws and tripod- 
head proper. By turning one or the other of them around their com- 
mon centre the instrument can gradually be brought to a vertical posi- 
tion. The final levelling touches are given by means of the usual levelling- 
screws, which at the same time clamp the instrument firmly. The great 
advantage of this Quick- Levelling Tripod over other forms is that the 
instrument will not fall over even if it is not clamped, and no accident 
on this account can occur. 

It can be attached to any transit or leveling instrument. 

Price $10 00 

If ordered with a new instrument 7 50 



FAUTII & CO., WASHINGTON, D. C. 



43 




No. 51. 

RECONNOISSANCE AND MINING TRANSIT. 

This cut represents a complete Transit Theodolite, which is especially 
adapted for reconnoitring purposes, as it only weighs about 5 lbs. 
Horizontal and vertical circles are 4 inches diameter, graduated on silver, 
and both reading by opposing verniers to single minutes. The telescope 
has an aperture of 1J inches and magnifies about 20 diameter. 
Price, completely packed, with stand $200 00 

EXTRAS FOR MINING TRANSITS. 

Diagonal eye-piece, with adapter $20 00 

Illumination for telescope 10 00 

Brass lamp 8 50 

Plummet lamp, in gimbals, per pair 25 00 



44 



FATJTH & CO., WASHINGTON, D. C. 



LEVELLING INSTRUMENTS. 




No. 52. 

No. 52. — Level of Precision, as made by us for U. S. C. & G. 
Survey, for the most exact work, can also be used as a gradi- 
entor, the micrometer screw for raising or depressing the 
telescope being made with the utmost exactness, and being 
provided with a graduated head. The telescope has an 
aperture of 1^ inches, and 16 inches focus, with two astro- 
nomical eye-pieces, magnifying 40 and 60 times respectively. 
The pivot-rings are of phosphor bronze,and rest on agate. 
The striding level is chambered, and one division equals 
3 seconds of arc. The horizontal circle, of five inches 
diameter, divided on silver, reads to 30 seconds ; the centre 
is of steel ; clamp and spring tangent motion. Completely 
packed, with tripod $250 00 



FAUTH & CO., WASHINGTON, I>. C. 



45 



LEVELLING INSTRUMENT AND GRADIENTOR. 




H.H.NIDHQLS.SO. 
No. 53. 

No. 53. — Telescope 1J inch aperture, 10 inches focal length ; 
4-inch horizontal circle, vertical arc, both divided on silver 
and reading to minutes. By means of the gradientor attach- 
ment, angles of depression or elevation can be measured with 
great precision, as well as distances taken. The compass 
needle is 5 inches long, in oblong box under the striding-level ; 
this latter is ground and very sensitive. Packed complete in 
box, with all accessories, tripod stand $225 00 



46 



FAUTH & CO., WASHINGTON, D. C. 




FAUTH & CO., WASHINGTON, D. C. 47 

The above cut represents a Y level of the most approved form. The 
telescope has an aperture of 1J inches, and is about 16 inches long. It 
rests in the Ys on hard bell metal rings ; the level bubble is very sensi- 
tive ; centre long and compound ; four levelling screws. 

Price, packed complete $145 00 

Locke's Hand Level, in case, German silver $12 00 

". " " brass 10 00 



LEVELLING E0DS AND CHAINS. 

Philadelphia Levelling Kod $18 00 

New York " " 16 00 

Boston " " 16 00 

Grumman's Patent Chain, W. G. 18, with spring, level, thermom- 
eter, brass handles ; weight J lbs., 50 feet 17 00 

Land Chains, W. G. 8, brass handles, 50 feet 3 50 

Same, 100 feet 5 50 

" W. G. 12, 100 feet, bronzed links 11 50 

Chains in feet or meters to any length ; compared with the U. S. 
Standard. 



STEEL TAPES. 

Steel Tapes, in leather case, -J inch wide, divided in l-10ths or 

l-12ths and links or metres, 100 feet $16 00 

50 feet 8 50 

Pocket Tape, in nickel case, divided in l-10ths or l-12ths and 

meters, 25 feet - 6 00 



48 



FAUTH & CO., WASHINGTON, D. G. 

PLANE TABLE. 




No. 55. The above cut represents one of our Plane Tables with 

a portion of the board cut out to show the motion-work. The 
most simple and effective form of plane-table made. The 
bearing surface of the motion-work being 8 inches in diameter, 
the table, when clamped, is perfectly firm. The alidade rule 
is 20 inches in length, and carries a powerful telescope of 1^ 



FAUTH <fe CO., WASHINGTON, D. C. 41) 

inches aperture, and 15 inches focus. For easier adjustment 
of collhnation the telescope can be turned in its axis 180° 
without lifting it out of its bearings. The compass-box is 
detachable : needle 5 inches long ; striding level reading to 
minutes. Stadia lines for measuring distances, beside the 
ordinary cross-line, are ruled on glass diaphragm. The ver- 
tical arc reads to minutes. The board is 24 by 30 inches, and 
is provided with an extra packing-box The alidade packs in 
a box with a number of paper clamps, beside the usual acces- 
sories ; the motion work is also securely packed in a box. 
Price, complete, with firm tripod stand $300 00 



THREE-ARM PROTRACTORS. 

Protractors, as made by us for the U. S. Coast & Geodetic Sur- 
vey, with 6-inch circle, divided on silver, and reading to 
minutes ; the arms have extension-pieces to make them 30 
inches long ; glass centre with pricking-hole. Complete, in 
box $110 00 



TIDE GAUGES. 

Self-registering Tide Gauges, much improved, have been constructed 
by us for the U. S. Coast Survey and the U. S. Engineers. 
The roller system runs in a metal frame ; the large wheel is also 
of metal, and the clock is of superior construction with spring 
balance. Price $350 00 



50 



FAUTH cV CO., WASHINGTON, D. C. 




FAITH & CO., WASHINGTON, D. C. 51 

No. 56. — Magnetometer, as made by us for the United States 
Coast and Geodetic Survey. The magnet-box and small tele- 
scope, by which the scale of the intensity-magnet is read off, 
is detachable from the vernier-plate, and the standards, with 
the telescope of 1^-inch aperture and 7 inches focus, can be 
substituted ; it then forms a complete small Alt- Azimuth, large 
enough to get, with sufficient accuracy in magnetic work, time, 
azimuth and latitude. The circles are four inches in diameter, 
divided on silver, and reading by two opposing verniers to 
minutes. The telescope has prismatic eye-piece and sun-shade. 
The deflecting bar is of wood, four feet in length, in two 
pieces, so as to be easier to carry. It is divided to tenths of 
inches. The intensity-magnets have at one end a fine divided 
scale, (one division being equal to 5 minutes,) at the other end 
the collimating lens ; the scale is viewed through the small 
telescope of f -inch aperture and 3 inches focus ; tenths of 
divisions can easily be estimated. Rack and pinion move- 
ment in the glass tube to raise and lower the stirrup carrying 
the magnet. A riding piece fits on the deflecting bar, upon 
which the deflecting magnet is placed ; inertia-ring, twist-piece, 
beside all the usual accessories, go with the instrument. Price, 
complete, as shown on cut, packed in box, with tripod $400 00 

No. 57. — Magnetometer, as made by us for U. S. Corps of 
Engineers, with only one telescope, used both for determining 
the magnetic and astronomical meridian. The magnet-box is 
detachable from the vernier plate, and telescope can then be 
used to observe for time or azimuth. Two collimating 
magnets, deflecting bar, and all accessories go with it. Price, 
completely packed, with tripod 250 00 



DIP CIRCLE. 

No. 58. — Dip Circle, with two 3|-inch needles, swinging on agate 
and enclosed in glass case. Vertical circle 6 inches diameter, 
divided on silver, reading by two opposing verniers to minutes. 
Attached to the vernier arms are two reading microscopes to 
read off the magnets. The lower horizontal circle is also 6 
inches in diameter, and reads to minutes. Packed complete in 
one box, with two large steel magnets and needle-holder for 
convenience in magnetizing the needles, with all the usual 
accessories 300 00 



52 



FAUTH & CO., WASHINGTON, D. C. 



SEXTANT 




No. 59. 

The above cut represents our style of Sextant, which, although very 
light, is an exceedingly accurate instrument. 

No. 59. — Sextant of 7^ inches radius, divided on silver, and 
reading to ten seconds ; the cut shows all accessories, packed 
complete $110 00 



ARTIFICIAL HORIZON. 

No. (JO. — Artilicial Horizon, with mercury-bottle and trough, 

rectangular plate-glass cover, packed in mahogany box $25 00 



FAUTH & CO., WASHINGTON, I). C 



POCKET COMPASS. 




No. 61. 



No. 61. — Prismatic Compass, 3 inches in diameter, with divided 
ring on needle and folding sights ; packed in neat case, very 
convenient for reconnoissance $25 00 



HELIOTROPES. 




No. 62. 

No. 62. — -As made by us for the United States Coast and Geodetic 
Survey. The telescope body is an iron tube ; a wood screw 
with joint is attached at the middle, so that the instrument can 
be screwed to any tree or post. Mirrors of plate-glass. Price, 
in box $30 00 

No. 63. — Heliotrope, on tripod, with horizontal and vertical axis ; 

a graduated circle allows angles to be read off. Price, in box. 75 00 

No. 64. — Pocket Heliotrope, Steinheils, a beautiful instrument 

that requires no adjustment ; in case 20 00 



54 



FAIJTH & CO., WASHINGTON, D. C. 




FAUTII & CO., WASHINGTON, D. C. 55 

Cut No. 64 represents a perfected form of the Contact-Slide Base 
Apparatus, used in the C. & Gr. Survey., designed by Prof. J. E. Hilgard, 
Sup't of that Survey. We have made several of this pattern for colleges 
and Government Departments. 

The apparatus consists of two measuring bars 4 meters long, exactly 
alike, supported on trestles. The measurement is made by bringing 
these bars successively in contact, which is effected by means of a screw 
motion and denned by the coincidence of lines on the rod and contact 
slide. Each bar consists of two pieces of wood about 8x14 c. m. 
square and a little less than 4 meters long, firmly screwed together. 
Between the pieces of wood is a brass frame carrying three rollers, on 
the central one of which rests a steel rod about 8 m. m. in diameter. 
On each side there is a zinc tube 9 m.m. diameter. The rod and tubes 
are supported throughout then length on similar systems of rollers. 
The zinc tubes form with the steel rod a metallic differential thermom- 
eter, and are so arranged that one tube is secured to one end of the rod, 
being free to expand in the other direction, the other tube being in a 
like manner fastened to the other end of the rod. The zinc tubes, there- 
fore, with any change of temperature, expand or contract in opposing 
directions, and the amount by which the expansion of the zinc exceeds 
that of the steel is measured by a fine scale attached to the rod, while 
the zinc tube carries a corresponding vernier. The cut shows this 
arrangement, which is identical on both ends of the bars ; a perforation 
in the wood of the bar allows this scale to be read. In addition to these 
metallic thermometers a mercurial thermometer is attached to the bar 
about midway of its length. 

The rods and tubes thus forming a united whole are lengthwise 
movable on the rollers by means of a milled nut working in threads cut 
on the steel rod, which passes through a circular opening in the brass 
plate screwed to the wooden bar, and against which the nut presses. 
Two strong spiral springs pull the rods back, and the nut is always 
pressed against the plate. 

One end of the rod is defined by a plain agate securely fastened to it ; 
the other end carries the contact slide, having an agate with a horizontal 
knife edge. This slide is a short tube, fitting over the end of the rod, 
and pushed outward by a spiral spring. A slot in the tube shows an 
index plate, with a ruled line fastened to the rod. 

To align the bars properly a small telescope is placed on each bar, 
and can be adjusted to bring the line of collimation over the axis of the 
rod. The trestle, shown in the upper left hand corner of the illlustration, 
consists of a strong tripod stand, carrying a frame with two upright 
guides for two crow slides, which are separated by a movable wedge. 
These cross slides can be clamped in any position. By moving the 
wedge, the bar resting between the uprights is either elevated or de- 



5() FAUTH & CO., WASHINGTON, D. C. 

pressed. To obtain smooth movements, friction rollers are provided. 
To move the bars sideways, a coarse screw takes hold of a projection on 
the lower side of the bar ; by turning which, the bar can be moved 
laterally. 

There are three pairs of trestles, alike in construction with the excep- 
tion that the upper slide of the trestle intended for the forward end of 
the bar carries a roller on which the bar rests, while the other has a fixed 
semi-cylindrical surface for the support of the bar. In making the 
measurement, the bars being four meters in length, the stands are set 
up at distances of two meters, each bar being supported at one-fourth 
its length from the ends, as indicated by the painted black bands. 

Each bar has a sector with level alidade attached to one side, by which 
its inclination can be read off to single mmutes. 

All base bars constructed by us are compared with U. S. standards. 

Price of the whole apparatus, including two bars and six 

trestles $450 00 

Price of simple 4 meter Standard Bar 90 00 

" of Abutting piece and Level Comparator to test bars 125 00 

Note. — Bars of the same construction, in feet instead of meters, can 

be furnished on order. 



FAUTII & CO., WASHINGTON, D. C. 



0) 

-o 
m 
O 
H 
J) 
O 

m 

H 
m 

30 




58 



FAUTH & CO., WASHINGTON, D. C. 



Cut No. 65 represents a very complete Spectrometer, according to the 
plan of Prof. C. A. Young. 

We have made several sizes of this instrument, with circles from 12 
to 18 inches in diameter, and telescopes from 2 to 2-J inches aperture. 
The circle is graduated into 5 minute spa ces and read by means of two 
micrometer-microscopes to single seconds ; these microscopes are 
attached to the arm carrying the observing telescope. The collimating 
telescope can be turned on a separate axis by itself, and the whole in- 
strument can be rotated on another axis. The grating table, which is 
provided with all the necessary adjustments, turns on a centre of its 
own and has attached to itself two verniers reading to five seconds on 
the graduation of the circle. Both telescopes turn in adjustable Y's, for 
which purpose a sensitive striding level is provided. 
The price of these instruments varies, according to size, 

from $600 to $1,200 00 




No. 66. 

SPECTROSCOPE, 



FAUTH & CO., WASHINGTON, D. C. 59 

The preceding cut represents the form of spectroscope as made by us. 
It answers both for physical and astronomical research, and is arranged to 
be used either with diffraction grating or prism. It consists of a circu- 
lar box into which the collimator and observing telescope are screwed 
The collimator slides in a tube so as to bring the slit into the focus of 
the objective. This tube is connected with the adapter by four stiff rods, 
leaving the slit easily accessible. The collimator tube is graduated into 
millimetres. Grating or prism can readily be placed in the box on a 
small table which has all the necessary adjustments. By means of a 
milled head, projecting through the bottom of the box, the grating or 
prism can be rapidly rotated. A slow motion can at once be obtained 
without previous clamping by turning a tangent-screw fitted into the 
periphery of the grating holder, which is held by friction to a plate to 
which the projecting knob is fastened. The amount of rotation is meas- 
ured to single minutes by a graduation on bottom of box. When the 
grating is in use the collimator and view telescope are placed as shown 
on cut, forming an angle of about 38 degrees. When the prism — which 
is a dense flint — is to be used, the view telescope is changed and screwed 
into a collar on the side of the box. The two telescopes are then placed 
in a position of minimum deviation for the ultra-violet rays. The instru- 
ment can be put into any position by means of an universal joint. It 
is readily lifted off the stand when intended to be used with the telescope. 

No. 66 — Spectroscope as above, with telescopes of one inch 

aperture, about 9 inches focus, extra dense flint glass prism. $200 00 
No. 67 — The same, with telescopes of 1^-inches aperture and 12 

inches focus 250 00 

No. 68 — Spectroscopes on the above plan, of much simpler 

construction, either for gratings or prisms , 75 00 

No. 69 — McLean's Star Spectroscopes, consisting of a cylindrical 

concave lens in front of a direct vision prism 25 00 

This Star Spectroscope can also be used with above spectroscopes by 
attaching it opposite the observing telescope and taking off the collima- 
tor, making the instrument complete for stellar, solar, and physical work. 

We are happy to state that we have made arrangements with Mr. I). 

C. Chapman, who is well known as having been Mr. JRutherfurcT s 

assistant in the manufacture of diffraction gratings, to rule gratings 

for us. A new engine, provided with all the improvements which his 

familiarity vnth this hind of work suggested, is now being built by us. 



60 FAUTH & CO., WASHINGTON, D. 0. 

EYE-PIECES AND MICKOMETEES. 

POSITIVE EYE-PIECES. 

Ramsden — J inch to J inch equivalent, each $4 50 

1 " H " " " 5 00 

If " 2J" " " 6 00 

Kellner (achromatic) — J inch to f inch equiv., each 6 00 

I " " " 7 00 

li " " " 8 50 

II " " " 10 00 

Steinheil (achromatic) — J inch to J in cl>. equiv., each ... 9 00 

1 " " "..... 12 00 

NEGATIVE EYE-PIECES. 

Huyghens — J inch to 1 inch equiv., each $5 00 

li " li " " " 6 00 

Airy (giving a large and perfectly flat field) — J inch to ^ inch equiv., 

each 6 00 

£ inch equiv., each 7 00 

I " " " 9 00 

li " " " 10 00 

II " " " 12 00 

" 16 00 

TERRESTRIAL OR INVERTING EYE-PIECES FOR DIRECT 

VISION. 

Fraunhofer — J inch to J inch equivalent, each $7 50 

f " " " 8 00 

I " " " 10 50 

II " to 2 inches " " 15 00 

Airy (large and perfectly flat field) — J inch to ^ inch equiv., each. 8 50 

£ inch equiv., each 10 00 

1 " " " 12 00 

1J " to 2 inches equiv., each 16 00 

DIAGONAL TERRESTRIAL EYE-PIECES. 

1 inch to J inch equiv., each $18 00 

1 " 11 " " " 20 00 

REFLECTING PRISMS. 

First surface reflecting prism (solar) $15 00 

§ inch square, mounted with sunshade 7 50 

l " " " " " 10 00 



FAUTII & CO., WASHINGTON, D. C. 61 

J inch square, mounted with sunshade 15 00 

1 " " " " " 20 00 

Helioscopic eye-piece, Merz, modified by Prof. Young, according to size, 
from $50 up. 

MICROMETERS. 

Eye-piece micrometer, (filar,) each $50 00 

Reading " with achromatic objective 65 00 

Position " according to style, from $75 up. 

Double image " " " from $75 up. 

Compensation Slides, of neutral tint glass, according to size, from $5 up. 

LEVEL VIALS, 

of all sizes and grades of sensitiveness, from $0.75 to $1.00 per inch. 
Chambered Levels, reading to seconds, from $3 to $5 per inch. 






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